1. Field of the Invention
The present invention relates to methods and systems for supplying power to a computer system, and more specifically to the methods and systems for controlling the amount of power consumed by computer systems.
2. Background of the Related Art
Modern data centers include large numbers of electronic components that require electrical power to operate. In fact, sufficient power capacity must be provided to support each of the electronic components over an operating range up to the maximum possible power that the components can draw. The maximum possible power drawn by an electronic component, or group of components, is sometimes referred to as the maximum label power. In a rack for supporting and operating computer systems, such as a group of servers and supporting hardware, the power circuits must be able to supply enough power to operate the rack at the most extreme configuration of components and the maximum workload scenario. This is the case even though the actual operating power may be only about 30% to 70% of the maximum label power. Furthermore, regulations generally require that the rack power circuits have the capacity to provide 20% more power than the sum of the maximum label power for each electronic component. Unfortunately, providing excess and unused power capacity increases infrastructure and operating costs. Furthermore, if the data center can support only a limited total power, excess power means that fewer electronic components can be installed in the data center.
Software power capping tools, such as ADVANCED ENERGY MANAGER (a trademark of International Business Machines Corporation, Armonk, N.Y.), can be used to limit the power consumption of a computer system. However, because software is subject to modification or failure, regulations generally prohibit reliance on software to control the total power to the system.